[1] Univ Hawaii, Sch Ocean & Earth Sci & Technol, Honolulu, HI 96822 USA
[2] Natl Ctr Atmospher Res, Boulder, CO 80303 USA
[3] Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30322 USA
[4] Univ Minnesota, Particle Technol Lab, Minneapolis, MN 55455 USA